Distributing pieces of knowledge in large, usually distributed organizations is a central problem in Knowledge and Organization Management. Policies for distributing knowledge and information are very often incomplete, or conflict with each other. As a consequence, decision processes for information distribution may be difficult to formalize on the basis of a rationally justified procedure. This paper presents an argumentative approach to cope with the above problem based on Defeasible Logic Programming, a logic programming formalism for defeasible argumentation. Conflicts among policies are solved on the basis of a dialectical analysis whose outcome determines to which specific users different pieces of knowledge are to be delivered.